396 HYALONEMA (THALLONEMA) GEMINATUM. 



anchor lies on the same side of the shaft as the shortest side of the other. The 

 dimensions of a typical amphidisc of this kind are: — total length 22 /x; thick- 

 ness of shaft 1.5 m; length of the longest and shortest parts (sides) of the anchors 

 respectively 7.5 m and 4 yu ; breadth of anchors 9 m- 



The nearest allies of the above sponge are Hyalonema (Skianema) aequa- 

 toriale and H. (S.) umbraculum described in this Report. From both it is 

 distinguished by the possession of large geminate macramphidiscs and small, 

 long-spined canalar pinules, and by other differences in the spiculation. 



